The objectives are a) to present Antonovsky's concept Sense of Coherence (SOC) and his 13-item SOC-scale, b) to describe the distribution of SOC in a random sample of five age groups in the Danish population, and c) to study the association of SOC to sex, age, social class, and health. The Danish Longitudinal Health Behaviour Study (DLHBS) collected self-administered questionnaire data from a random sample of the population born in 1975, 1965, 1940, 1930, and 1920. The baseline study took place in 1990, response rate 71%, n = 2,858. The article reports data from the first follow-up in 1994, response rate 86% of the survivors, n = 2,352. SOC shows no gender differences; it is significantly lower in the youngest age group and increases with age. SOC is highest in the highest social classes. Poor SOC is associated with poor self-rated health and high prevalence of symptoms. Poor SOC is associated with high prevalence of long-term illness among respondents older than 50 years of age.